Rail erake



Aug. 8, 1950 Filed Oct 9, 1946 Fly. 1.

' P. MADSEN RAIL BRAKE 2 Sheets-Sheet 1 I NVENTOR= PETER MADSEN P. MADSEN 2,518,346

RAIL BRAKE 2 Sheets-Sheet 2 I VENTOR PETER MADSEN Aug. 3, 1950 riled Oct. 9, 1946 Patented Aug. 8, 1950 OFFICE BAIL BRAKE Peter Madsen, Valby, near Copenhagen,

Denmark Application October 9, 1946, Serial'No. 702,135,

In; Denmark August 25, 1945 Section 1-, Public Law 690, August 8, 1946 Patent expires August 25,1965

5 Claims. (01. 188-41.)

in order to increase the retardation of" the tramcar or the railway train. 7

However, it-has been found that the eifectivitvof the rail brakes; either they operate on a mechanical principle, by pressure air; or by vacuum, or as an electromagnetic brake, varies to a great extent according to the wear of the rails. The reason of this variation in braking effect on new'and old rails is mainly". due to the fact that the running surface of the rail, which in new rails is practically horizontal, in use is worn down, and this wear may provide the rail surface with an incline of up to- 8 This means furthermore, that the hitherto known rail brakes, which were either rigidly fixed in pairs each actuating one of the rails, or were guided in relation to the 1- vehicleand only able totread on a comparatively small part of its surface on the rail, thus provide only a small braking surface and a corresponding slight braking effect. Naturally this was most disadvantageous in connectionwith mechanically operating brakes, but still worse in connection with electromagnetically operating" brakes, in which a space between the brake shoe (the magnet) and the rail resulted in a considerable increase of the magnetic resistance, this being 2600-1090 times as great in air as in iron, according to degree of saturation; It is thus apparent that even a veryslight space between the rail and the brake magnet will considerably increase the magnetic resistance and thus reduce the number of lines of force, and accordingly likewise the tensile force (braking capacity).

'In the last mentioned type of brake with which the effect of the worn rail is most predominant, various proposals have been made to remedy this drawback. Thus for instance the lower surface of the brake shoe has been provided with an incline of 3 to the effect that the greatest angle between rail of surface somewhat worn rails and the brake shoe surface would not exceed more than 4-5".

Even though this arrangement to some extent remedied matters in connection with considerably worn rails, the braking effect on new rails with horizontal surface was also reduced, for which reason this solving of the problem was not the best.

It has furthermore been proposed to provide the brake shoe with a yielding wearing surface by providing it with transverse incisions. Besides weakening the brake shoe considerably this mannor of solving the problem is subject to a number of other drawbacks, to the effect that neither in this way is there obtained a solution of the problem of obtaining so large a portion of the brake shoe surface as possibleto tread upon the rail during the braking actuation, irrespective of this rail being worn or not.

It has furthermore been proposed to suspend the brake shoe in such a manner that it could adjust itself to the incline ofthe rail surface, but none of the hitherto known constructions have given satisfactory results, because during the braking actuation so great friction occurred in the parts through which the braking force should be transmitted from the shoe to the vehicle that it was not possible to turn the shoe in such a manner that it could abut the entire. wearing surface of the rail.

According to the present invention the. problem is solved by the rail brake shoe that is suspended in its vertical plane in which position it is adjustable, and during braking actuation treads upon the rail surface, being somewhat rotatably suspended in such a manner that when during brake actuation, it contacts the rail, it may freely adjust itself transversely until full abutment of the brake shoe. on the rail surface is attained. This transverse adjustment is obtained by means of a jointed connection formed by an eye enclosing a stud on the rail brake and a driver column attached to the vehicle. To facilitate the adjustability the eye may by the stud or by the column, or by both of these members have a somewhat larger diameter than the diameter of the stud and the column respectively, as likewise the cooperating members may be arched.

During braking actuation it is thus possible for the brake shoe to move with slight friction on the driver column, which movement practicall takes place at a single point on the column. Thus the brake shoe is able to adjust itself irrespective of the condition (wear) of the rail, and may tread with its entire surface against the rail surface for thus producing the greatest eifectivity.

In the drawing various manners of performances of the invention are illustrated, thus Fig. 1 shows schematically a new rail and a brake shoe in section,

Fig. 2 the same with a worn rail;

Fig. 3 a cross section through an electromagnetic rail brake,

Fig. 4 a side elevation of same, I

Fig. 5 a top elevation of same, and

Fig. 6 four electromagnetic rail brakes arranged in the chassis of a rail vehicle.

Referring to Fig. 1 a new rail with horizontal wearing surface is indicated by I, and 2 indicates a rail brake. In Fig. 2 the rail brake is indicated by 3 and the rail by 4, the surface of this rail being slightly inclined as indicated by 5, and from this will be seen how slight the contact is between the brake shoe and rail during braking actuation. In Fig. 3, 6 and 1 indicate the pole shoes, the ends of which are to tread on the rail 13 during braking actuation. ll indicates the magnet core, and I2 is a hinge that is rigidly attached to the one pole shoe and having its fulcrum in the vertical plane of the pole shoe.

In Fig. 4 the rail brake is indicated by I4, the lower surface I5 of the brake shoe treads on the rail 16 during braking actuation. l1 indicates a hinge having a hinge pin l8 inserted through an eye I9 that further-more embraces a driver column rigidly, attached to the vehicle, which arrangement, however, is not shown in the drawing. Zlindicates two lugs which by means of a Stlld'IlOt shown holds the spring in which the rail brake is suspended from the vehicle.

In Fig. 5 the one pole shoe of the rail brake is indicated by 22, and 23 indicates a magnet coil, while 2 1 indicates the other pole shoe to which there is weldeda hinge 28 that is connected to the driver column 2'! by means of an eye 25, which eye likewise embraces the stud 25 on the hinge.

In Fig. 6 the chassis of a rail vehicle is indicated by 3|], its wheels by 3|, and the wheel shaft by 32. 33 indicates a rail brake that is suspended in a spring 34, the one end of which is attached to the lug 35 rigidly attached to a bar 39 resting npon the shaft bearings. and 3'5 indicate hinges attached to the rail brake33, the pins of which hinges are engaged by eyes 38 and 39, each of which embrace driver columns 40 and ll respectively, whereas 12 and 43 indicate lugs attached to the vehicle and to which the driver columns 40 and 4 I respectively are attached. 4G, 45, and 46, indicate cross bars of the vehicle, and 41 and 08 indicate the rails upon which the vehicle runs.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

' 1. In a vehicle brake for track vehicles, the combination of a brake shoe adapted to be applied to the track; means secured to the chassis of the vehicle and the top of said brake shoe for adjustably suspending the same in a vertical direction; a pair of generally vertically extending rods secured to the chassis of the vehicle; a pair of pinties secured to said brake shoe; and connect ing members one each extending in a generally horizontal direction and in loop form around said rod and pintle so as to be relatively movable thereto.

2. In a vehicle brake the combination as claimed in claim 1, wherein the opening defined by saidlooped'member is larger than the individual diameters'of each rod and pintle.

3. In a vehicle brake the combination as claimed in claim 1, wherein the opening of said looped member is larger than the aggregate diameters of one rod and pintle pair.

4. In'avehicle brake for track vehicles, the combination of a brake shoe adapted to be applied tothe track; means secured to the chassis of the vehicle and the top of said brake shoe for adjustablysuspending the same in vertical direction; a pair of generally vertically extending stationary attaching members secured to the chassis of the vehicle; and two connecting means each movably attached to said brake shoe, each facing one of saidvertically extending stationary attaching members and including a loop-shaped member extending around the corresponding vertically extending stationary attaching member so as to be movablerelative thereto.

5. In a vehicle brake for track vehicles, the combination of a brake shoe adapted to be applied to the track; means secured to the chassis of the vehicle and the top of said brake shoe for adjustably suspending the same in vertical direction; a pair of generally vertically extending stationary attaching -members secured to the chassis of the vehicle; a pair of movable attach:- ing members secured to said brake shoe, each facing one of said stationaryattaching members; and two connecting means, each extending in a generally horizontal direction attached to said brake shoe by one of said movable attaching members and extending in loop form around the corresponding vertically extending stationary attraching member so as to be relatively movable thereto. 1

PETER MADSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 285,507 Patterson Sept. 25, 1883 290,689 Kampfe Dec. 25, 1883 768,357 Corey Aug. 23, 1904 1,235,103 Botz' July 31, 1917 1,645,741 Elliott Oct. 18, 1927 1,651,524 Hershfield Dec. 6, 1927 2,096,486 Farmer Oct. 19, 1937 2,130,615 Grittenden Sept. 20, 1938 2,178,643 Piron Nov. 7, 1939 

